This invention relates to reflective projection-type displaying apparatuses.
Reflective projection-type displaying apparatuses have been used for displaying pictures on a wide screen. The apparatuses are provided with a liquid crystal display (LCD) panel. Light beams enter the panel where the beams are modulated per pixel in accordance with video signals and are projected onto a screen to display pictures.
Displaying apparatuses provided with a reflection-type LCD apanel are generally useful than those with a transmission-type LCD panel. Because the reflection-type LCD panel does not require a black stripe on the liquid crystal layer and hence exhibits large vignetting factor on each liquid crystal cell. Furthermore, the reflection-type LCD panel generates less heat that would be produced to absorption of light beams, thus producing light beams of large emission output to display blight pictures on a screen.
Japanese unexamined Patent publication No. 1997(9)-189809 discloses a displaying apparatus provided with a reflection-type LCD panel. The apparatus is further provided with a holographic color filter that exhibits the maximum optical efficiency when light beams enter the filter at an incident angle of about 60 degrees while the beams having been almost perpendicularly entered the plane of incidence of the apparatus.
The larger the plane of incidence, the higher the illumination efficiency. This apparatus however cannot provide the plane of incidence large enough for achieving high illumination efficiency due to its optical construction.